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An Opal-Calcite Composite
A Useful Technique to Confirm the Hydrophane Nature of Opal
Observing a water drop’s interaction with opal, as well as refractive index, can confirm a specimen’s hydrophane nature with less risk of breakage than total immersion.
Hydrophane Opal Treatment
An opal rough is immersed in water and treated with oil and Opticon to observe effects on transparency and play-of-color.
Rare Double Pseudomorph Ikaite-Calcite-Opal
New Deposit of Black Opal from Ethiopia
The Stayish mine in Ethiopia’s Wollo province has been producing black opal since 2013.
Inclusions in Natural, Treated, Synthetic, and Imitation Opal
Provides a visual guide to the internal features of natural, treated, synthetic, and imitation opal.
Land of Origins: A Gemological Expedition to Ethiopia
Documents a visit to the sapphire, opal, and emerald mining and trading areas of Ethiopia.
Snowflakes in Opal
.jpg "YMAL GIA Ed")
